Facsimile system



Mardi 7, 1939. J. v- L. HOGAN I 2,149,292

FACSIMILE SYSLEM Filed June 16, 1954 3 Sheets-Sheet l Jo/r/v YL Haan/v4, Hok/:cf 6. /V/urfr INVENTORS -March 7, 1939. 1, v. L HOGANFAcsMILE'sYsTEM 3 Sheets-Sheet 2 Filed June 16, 1934 Jo//w V. L. own/V,40,7465 6. M/um INVENTORS March 7, 1939; J. vl L. HOGAN FACSIMILE SYSTEMFiled June 16, 1934 3 Sheets-Sheet 3 .5m/WARD Hna/0 fcf/ VER JoH/v V1.Hoda/v44 Hok/wf N/LLER a INVENTORS Patente'dMar. 7, 1939 v`UNITEDY,STATES PATENT ol-Flcu FACSIIVIILE SYSTEM tion of New York ApplicationJune 1s, 1934, sei-m1 No. 130,856

5 Claims.

This invention relates to facsimile transmission systems and the like.By facsimile system is meant a system for the transmission to distantpoints of records, especially records printed, writ- 5 ten, drawn orphotographed upon the surface of some medium such as paper, film, or thelike.

Such systems utilize at the transmitter records,

the various portions of which have different light.

reactive properties and reproduce at the receiver l a so-calledfacsimile of the record which was acted upon at the transmitter. Suchfacsimile reproductions are not necessarily extremely precise oridentical copies of the record at the transmitter, but may approximate,in exactitude, the

l i matter to be transmitted merely to such degree as will serve to givea reproduction satisfactory for a particular purpose desired.

This invention deals more particularly with facsimile transmissionsystems where a graphic 80 record is acted upon by electro-opticaltransla-4 tion means, including a photoelectric cell and the electricalsignals thus produced correspond in value to the light reactiveproperties of the various portions of the matter to be transmitted. At

i 25 the receiver a translation of these electrical signals gives riseto an optical reproduction of the material acted upon at thetransmitter. The transmission link between the transmitter and thereceiver may be, for example, a physical line 30 ora radiant energychannel.

One embodiment of this invention optically analyzes the image to betransmitted by a scanning process and causes the reproduction of suchimage upon a surface of paper or similar material 36 at the receiver inthe form of marks upon such ployment of ink to be made upon' ordinarypaper not especially prepared or treated for the pur- 50 pose, at afacsimile receiver. This is in contrast to many facsimile reproducingdevices previously proposed or now in use, which produce records not aspermanent as those of the ink type, or else require the employment ofelectrochemical, 55 thermochernical, photochemical or other treatedappearance of the reproduced image.

(C1. ris-6.1)

ical surfaces and with the inconvenience inherent in the use of chemicalagents.

Suchphotographic processes as those last referred to, which requiresubsequent chemical treatment, have the further disadvantage that anymaladjustment or improper functioning of the receiving device, such aslack of synchronization with the transmitter, cannot be perceived by theoperator of such a receiver until the entire transmission has ended andthe photographic' record has been developed. This invention avoids suchdiculties by making a record which may be instantly visible to theoperator and thus allows him to see and correct at once anymaladjustment of the receiver, withoutV losing an entire transmissiondue to any material delay in the Furthermore this invention, bydispensing with the use of photographic paper or other electrochemicalor thermochemical responsive surface allows a great gain in economy ofmaterial and simplicity of operation, even to the extent of removingsuch. reproduction process from the status of an operation necessarilyconducted by skilled technicians, to one which can be conducted by anordinary layman capable of operating the u'sual household radioreceiver.

Another object of this invention is to produce a facsimile reproductionwhich may be termed "continuous. Many types of previous facsimilesystems have employed a surface whose area was limited; for example, asingle sheet of paper of limited length Wrapped once around acylindrithe following reproduction. This invention allows theutilization of a so-called continuous type of record paper. A roll ofpaper having very great length in vone dimension may be employed withthis invention, thus reducing changes of the record necessarily made bythe operator to a minimum number. This invention allows a similarcontinuous strip to be used at the transmitter.

Another object of this invention is to allow facsimile transmission andreproduction at high B5 rates of speed, such that, for example, eventsof current interest such as important news items or financial quotationsmay be made available with such rapidity and accuracy as to comparefavorf ably with more complicated systems now used for such purposes,such as printing telegraphs and l the like. This invention allowsadequate detail to be maintained in such cases, evenwith high speedtransmission.

A further object of this invention is to provide a facsimile reproducerwhich shall be able to function for long periods without the necessityfor any attention on the part of an operator.

Such automatic operation will allow a facsimile reproducer giving apermanent record according to this invention to be employed over wire orradio channels during periods of the day when such channels are carryingthe minimum amount of traffic and thus may be of great benefit inallowing such channels to be more elciently employed than is at presentpossible with the uneven load distribution extending over the dailyperiod of their utilization.

Still another object of this invention is to provide a facsimilereceiver which shall be simple and cheap in construction and which canbe employed in conjunction with household receiving apparatus such as areceiver for broadcast radio signals, notwithstanding that such radioreceiver may have a' normally poor response to low fre- Y quency signalssuch as those used in a facsimile transmission. A facsimile receiver ofthis type presents a wide field of utility in that it may be employed inhousehold use as an appendage to types of radio receivers which arealready to be found in widespread use in such locations or in otherplaces where they must necessarily be capable of satisfactory operationby those who are laymen with respect to the electrical art.

Another object of this invention is to allow facsimile transmission bythe employment of electrical signals which will not easily be confusedwith or interrupted by stray or static im-V pulses or so-called noiseeffects originating in the terminal apparatus itself or elsewhere.

This invention may be used to produce such signals, particularly whenonly two light values are used for reproduction, as above described.

Such a system allows substantially maximum i verse reproduction of theobject employed at the transmitter to be obtained at the receiver. Sucha feature is of great practical utility in allowing the employment ofphotographic negatives without the necessity of making positive copiesthereof, and yet allowing the reproduction to be obtained as a positive..It thus may employ either optical type of object, i. e., positive ornegative, at the transmitter by an extremely simple change of adjustmentthereat, while the receiver may easily be adjusted to reproduce suchoptical objects in correct or natural form. In this fashion thisinvention reduces the time necessary between the photographing of somescene or object to be transmitted and the actual transmission thereof.For example, news events may inY this fashion be transmitted in a Veryshort time after their actual occurrence.

Yet another object of this invention is to allow material written bymachina' for example, a typewriter, to be transmitted with the minimumdelay between its printing and its actual transmission and reception.

Another object is to transmit facsimile signals in such fashion that apen at the receiver may remain in contact with a recording surface whennov signals are being received, giving a pensealing effect when thereceiver is not in use and avoiding-unwarranted evaporation or drying upof writing fluids used with the pen.

A further object of this invention is to provide a photoelectrictranslating systemy where alternating current is employed in connectionwith a photoelectric cell in such` fashion that high percentagemodulation may be obtained, notwithstanding the electrostatic capacityinherent in such cells.

`Further objects of this inventionare to provide means for illustratingradio lectures and the. like by graphical illustrations simultaneouslytransmitted, to allow a permanent record of formulae, quotations, or thelike to be obtained by a listener without the necessity for any efforton his part in transcribing the same. n v Other objects of thisinvention are to allow the transmission of broadcasting of financialquotations, weather reports', andl similar groups of figures or separatewords which may be easily confused when received solely through the earand to allow broadcasting stations to obtain a definitely measurableindex o f station coverage and program popularity.

This invention may be understood by refer-v ence to the drawings whereFig. 1 is a block diagram representing the Various cooperating unitswhich may be employed with one'form of transmitterY embodying thisinvention. Y

Fig. 2 is a block diagram representing an alternativeassembly of unitswhich may be em- -ployed withv another form'fof .transmitter embodyingthis invention.

Fig. 3 shows a modified form of the structure of Fig. 2. l

Fig. 4 shows a transmitter -with certain portions in greater detail andshowingI details of certain circuitsembodying novel features.

Fig. 5 shows schematically and without unnecessary detail, certainelectromechanical and optical elements Vused Yto form a transmittingscanner whichrrnay be employed in conjunction with the electricalcircuits indicated in Fig. l.

Fig. 6 shows partly schematically certain elements which may be employedto form a complete receiver and certain of the circuits thereof.

Fig, '7 shows certain details of a receiver suit'- able for operationwith the system-of this invention.

Fig. 1 shows a block diagram of a facsimile transmitter according tothis invention in which the component parts and their fun-.tions havebeen simplified. Referring to this iiguf.. an oscillator 3 operating `ataisub-carrier frequency such as 2400 cycles per second is shown. The

output voltage of' this oscillator is delivered to av balanced-modulator4 having a photo-electric cell as the modulating element. A mechanicalor other type scanning system 5 may be employed to scan the subject tobe transmitted and transmits lightimpulses of varying intensity,depending on the various optical densities of different portions of theobjectto be. transmitted, to the photo-electric cell.' The output of thebalanced modulator, consisting of pulses of sub-carrier freceived by thephoto-electric cell, is fed to an amoscillator. A here'shovyn, bederived from the sub-carrierespliiier 6 tuned to the sub-carrierfrequency and capable of passing at least one side-band of the modulatedsub-carrier frequency, preferably at least as great as the frequency ofthe scanning system light pulses. 'I 'he output of the tuned amplifieris fed to a modulation system 'l where it modulates thecarrier-frequency signal to be transmitted to the distant receiver.

'I'he carrier modulated by the sub-carrier pulses may be radiated at anyradio frequency,-

such as 1650 kilocycles from an antenna I in conjunction with a groundconnection 2, or any other suitableradiating system may be used.

'Ihe radiated carrier wave of i650 kilocycles, in this instance, isdoubly modulated by (a) the 2400 cycle sub-carrier and (b) the scanningimpulses of still lower frequency which modulate the 2400 cyclesub-carrier.

Fig. 2 shows a block diagram of a system which embodies some refinementsoverthe system of Fig. 1 by the addition of a keying system and a systemfor generating a back stroke signal for the receiver recorder. Theoperationof the system of Fig. 2 is similar to that of Fig. 1 up to theoutput of the tuned amplifier 6, at which point the modulatedsub-carrier pulses are rectied,'as by detection means 8 such as athermionic diode circuit included at this point, and the pulses ofrectified current are fed to a keying relay 9. The keying relay thusoperated is used to turn off and on an alternating voltage which may, ashere shown, be derived from the sub-carrier The back-stroke signal mayalso, as

cillator. 'I'he back-stroke signal is turned on and the picture signalis turned o' by a switch operated synchronously with the scanningsystem, during each return or non-operative stroke of the scanningprocess. One form', of this switch and the purpose of the back-strokesignal will be later described in connection' with Fig. 5. The keyedsignal and Aback-stroke Asignal corn- -prising, for example, a 2400cycle tone, are used to modulate the carrier frequency. The modulatedcarrier frequency energy may then be radiated from the antenna as inthecase of Fig'. 1.

Fig. 3 shows a'systern similar tothat of Fig..2 with the modificationthat a second source of s ubcarrier frequency energy such as generatorI0 is used to supply the back-stroke signal and the keying'relayoutputor picture signal. The.sec-- plaining in greater detail the system of'Fig.v 3,

reference numeral 3 denotes the sub-carrier oscillator, or similardevice for producing an electric current of Ydefinite frequency andintensity. Such oscillators are well known in the electrical art andsince there may be used any suitable type, such as a type employingresonant circuits and/or piezoelectric crystals, it is not considerednecessary to illustrate the internal circuits of such oscillator indetail.

It is likewise-possible to employ In place of the type oscillator justdescribed, another type oscillator which is controlled or exteriorlygoverned by some other frequency, such as the frequency of a commercialpower circuit which serves to supply energy to the entire transmitter.In many cases auch secondarily controlled types of oscillatorsV willbefound advantageous.

. Oscillator''-1.13Qactstri:produce any alternatingV currentofsubstantially constant frequency and intensity whichsivesfas a carrierof the picture signal throughout lthe amplifying system employed aft-thetransmittei-gv` The frequency produced f by this 'oscillatorispreferably chosen higher than-,any frequencypr'oduced by the modulationof the photoelectric cell, in order that it may more satisfactorilyfunction as a carrier of the signals produced by'such modulation.

At 2l is indicated a. transformer with primary winding 22 and secondary.winding 23, serving to couple oscillator 31to photoelectric cell 24.Secondary winding 22 is tapped at a point intermediate the extreme endsof the winding, as indicated by reference numeral 25. One end of thesecondary winding is connected to one element of photoelectric cell 24and the other end of winding 23 is connected to the other terminal ofphotoelectric terminal 24 through an adjustable resistance 26 and anadjustable condenser 21 connected in series with one another.

When condenser 21 and resistance 26 are adjusted so as properly tocorrespond with the resistance and capacity of photoelectric cell 24, anelectromotive force will be impressed through these two elements uponphoto-electric cell 24 in such phase relationship and to such degree asto balance or compensate for the sub-carrier voltage which passesthrough cell 24, when no light is falling upon the cell. This balancedmodulator circuit constitutes a feature of great practical importancesince it allows an alternating current to be employed in connection witha photoelectric cell, and still permits the useful output of the cell tobe modulated through a wide range of values. If such a balancing orcompensating circuitis not employed, the alternating carrier currentfrom-:oscillator 2 0 will pass through cell 24, even when .this vcell isnot illuminated, andin many cases ,the current thuspassing through thecell will be of a lmagnitude so much greater than 'that of the'currentdue to the Aillumination of the cell, as practically tovcompletelyovershadow the latter.

tially every half-cycle ofthe sub-carrier oscillator. Afterpassingthrough'a transformer or similar device, it is evident that such signalagain will become an alternating current.

The intensity of this sub-carrier signal is proportional to the amountof light acting upon the Following the cell 24, within practical limits.

rto

to operate on these low frequency'pulses. These current pulsescorrespondin frequency and intensity to the pulses of light falling onthe photoelectric cell 2d, While the amplitudes of the pulses from therectifier thus depend on the light values of the subject being scanned,thevoltages supplied to the later circuits by the closing ofA relaycontact 30 will have a constant maximum amplitude. Y

This transformation from varying amplitude pulses Ito constantVamplitude pulses also aids in eliminating any noise which may havebecome associated with the initial type of pulses. The back-strokesignal switch 3i connected to the relay by wires 32 also suppliesconstant amplitude signals during the back or non-recording stroke ofthe scanner.

. One means for operating switch 3i being shown later in Fig. 5, itsuffices to say here that it may be operated from some part of amechanical scanner stroke mechanism and may be synchronized with thereturn or non-operative stroke. Completing the operation of the'system,the keyed pulses and back-stroke signals are used to modulate a carrierwave and the modulated wave radiated from antenna i and ground 2. y

While a radio transmission system has beenv shown,'the invention is notlimited to radio transmissionas, for example, the carrier frequencyoscillator and modulator may -be omitted and the keyed pulses `andback-stroke signalsY may be fed directly Vto a wire line or recorded ona phonograph disc or motion picture lm.

One suitable form of pick-up scanner is shown in Fig. 5. A concentratedlight source d is used to shed light rays through a rectangularvaperture di in mask d2. Behind this aperture a suitable objective lens33, xed in a screen lili, is caused to reciprocate in the plane of themask, by the use of suitable mechanism not here shown. Film 55, whoseplane is parallel to the direction of inotion of lens 43, is movedcontinuously in a direc- Y through the agency ofV lens d3. Mask i5 withslot shaped aperture 4l, placed behind the lrn,

allows photocell to receive the light which has passedv through film d5.Scanning in one dimension is accomplished by the luminous Yspot fromreciprocating lens d3 passing across the ilm' in one dimension while themovement of the film gives scanning in the other direction.

Any suitable mechanism, as well known in the art, may be employed tosecure the relative rnechanical motions of the, various elements/ asabove described. I'

Wires il@ convey the electrical output oi' cell d8 to the circuits ofthe balanced modulator, and back-stroke signal switch 3i may be operatedby the motion of mask 63, which, through simple and well knownmechanical means may be arranged to open this switch at one end of itsstroke and close it again at the other end of its stroke. Thus as theimage of source d passes transversepen 66.

ly to thei'motion of the nlm, Vin one direction, scanning of the imageson the film is effected, while on the return or non-scanning stroke, theswitch 32 is automaticallyclosed to prevent effective'scanning, It isunderstood that any other suitable mechanical or electrical scanner maybe employed to produce facsimile signals, since this invention is notlimited to the form of scanner disclosed in Fig. 5.

Fig. 6 shows a receiving system embodying a standard broadcast or othertype radio receiver .5B connected to antenna 5l and ground 5i', acoupling unit lil and a recording pen li. Leads 52 and 5'3 are broughtout from the receiver, e. g. fromrthe primary of the transformer 52Vwhich supplies speaker 53', or from some other internal source of largeaudio signal energy. l

The demodulation in the standard receiver and subsequent audioamplification will result in pulses of sub-carrier frequency voltagecorresponding to the pulses of light falling on the photo-cell and tothe back-stroke signal pulse. The pulses of sub-carrier voltage acrosswires 52 and 53 may be applied to at least a part of the primary oftransformer 55 through condenser 54. Transformer 55 may be tuned in theprimary by condenser 55, and in the secondary by condenser 5l, to themodulated sub-carrier frequency or preferably to the centerof oneside-band thereof. The secondary voltage of transformer 55 may beapplied to a rectifier consisting of a diode having an anode 58 andcathode 59. An impedance 6U and a biasing battery 6i may beeconnected inseries with cathode 58.. Rectified pulses now will appear acrossimpedancev, which pulses (after filtering out the sub-carrier voltage bymeans of condenser 62 and inductance t3) are applied to the control gridof output tube 69, together with biasing voltage from battery 6i Outputtube G9 is shown as a pentode type but may be any other output tube ofsuicient power handling capacity and sensitivity. In the output circuitof tube 69 are pen voperating coils 54 and $35 arranged to actuatemagnetically pen element t5. A high voltage supply i6? (usuallypossessing appreciable internal impedance) is shown to operate tube 69.Coil 65 acts to create a polarizing .field for pen G6 and may beenergized as shown, by a current drawn through bleeder resistor 68, plusthe screen-grid current'of tube 69.

When a signal is impressed the plate current rises, and because of theveffective impedance of the high voltage supply 6l, the resistor currentfalls. However, the screen current simultaneously rises, and thecircuits may be so proportioned Y that the sum of screen and resistorcurrents,-i. e.,

the polarizing current in coil B5, remains substantially constant, oreven rises, when signals are received. Coil 6d is connected in serieswith the anode circuit of tube 69 and receives the rectied and amplifiedoutput pulses previously described. Coil 6d thus energized, drives theFig.l 7 shows in more detail the construction of one form of therecorder pen. A strip of recording paper Sli is fed over a platen 8ipreferably of cylindrical shape. The pen-driving mechanism consists ofan Yelectro-magnet 82 made up of coils Sd and 55 (Fig. 6) Wound around amagnetic core 83, and a small iron armature 8d which is magneticallyVacted upon by the electro-magnetV vcore 33 and is fastened to thepeureed. Pen point S6 with flexible ink feed tube 8i'preferablyconnected to an ink reservoir (not shown), may

be attached to one end of 'reed 85 and the other encl of reed 85 may besecured to mounting bracket 88, which in turn may be fastened to magnet82 and hence move with it. 'I'he direction of paper feed is indicated byarrow 89 and the preferred direction of the pen on the active or markingstroke is indicated by arrow 90.

The' pen pressing against the paper as shown produces a firm marking.With no signal being received, the pen is in contact with the paper andhence is marking uponit. When a pulse of current is fed to the coilsystem of electro-magnet 82, due to light falling on the photoelectriccell 24 and subsequent amplification, modulation, transmission,reception and rectification as` described above, the pen is lifted fromthe paper,

leaving a white space thereupon. Likewise onV its return stroke, the penis lifted from the paper by the action of theback-stroke signalpreviously described and no mark is made during this return passage.Each complete to and fro travel is accompanied by an appropriate motionof the recording paper in the direction indicated by the arrow 89. Anysuitable mechanism, not Ahere shown, may be used to secure this feedingmotion of the recording paper.

In case of transmission from a negative picture subject, pulses may begenerated at theortrans-` mitter corresponding to picture densitiesabove a certain value (instead of below a certain value as in positivetransmission), so that when received and recorded a positivereproduction is obtained. For such operation the balanced modulatordescribed in connection with Fig. 4 above will ordinarily be adjusted topass minimum sub-carrier current when the photoelectric cell is fullyilluminated, the consequent unbalance being produced by reduction ofphotocell illumination as the darker portions of the transmitted imageare scanned.

Another method of providing negative transmission is to'fitrelay 29(Fig. 4) with a backcontact 9| and so to reverse the phase of the signalmodulation by connecting it in place of the normal or front-contact 30,Either method effectively reverses the sense in which the systemoperates and provides "negative transmission as here described.

While we have shown certain details of apparatus and circuits in theforegoing description, it is to be understood that we arein no wiselimited to such particular forms as shown except in as f ar as definedin the following claims.

We claim:

1. An'electro-optical transmission sy'stem including a light sourceilluminating an image to be transmitted, image scanning means operatingaccording to a predetermined cycle, means for generating current of asub-carrier frequency high compared to the frequency of said scanningcycle, photo-electric means for modulating a portion of said sub-carriercurrent inl accordance with the light from said image, m'eans forrectifying said modulated portion of said sub-carrier current and forobtaining modulation-frequency currents therefrom, means forvcontrolling an additional portion of said sub-carrier current inmaining portion of said scanning cycle, and means for transmitting saiddoubly controlled additional portion of said sub-carrier current.

` means for controlling the amplitude of a 2. An electro-optical cyclictransmission system including a light source illuminating an image to betransmitted'means for generating a substantially sinusoidalv current ofsub-carrier frequency, photo-electric means for modulating a portion ofsaid sub-carrier current in response to the light from said image, meansfor rectifying said modulatedsub-carrier current and for obtainingcurrents of modulation-frequency therefrom, means for keying a secondportion of said sub-carrier cmrent operated by said modulation-frequencycurrents during a portion of a transmission cycle and other means forcontrolling said second portion of said sub-carrier current during theremaining portion of said transmissionV cycle, and means fortransmitting said keyed and controlled second portion of saidsub-carrier current.

`3. An electro-optical transmission system including a light sourceilluminating at least a portion of an image to be transmitted, meansvfor generating a substantially sinusoidal subcarrier, photo-.electricmeans for `amplitude modulating a portion of said sub-carrier inaccordance with the light from said illuminated image, means forrectifying said modulated subcarrier, means for obtainingmodulation-frequency currents from said rectified sub-carrier, secondportion of said sub-carrier operated by said modulation frequencycurrents, and means for transmitting said controlled portion of saidsubv carrier.

f sistance and capacity of said photo electric means under a givenillumination of said photo electric means, a reciprocating scanningmechanism for exciting said photo electric means, switching meansoperated by said scanning mechanism so as to be open when said mechanismmoves in one direction and closed when said mechanism moves in the otherdirection, a second source of sub-carrier alternating current,controlling means for the current from said second source and operatedby said switching means, other controlling means for the current fromsaid second source and operated by the modulated current from said photoelectric means, and means for transmitting signals corresponding to thecontrolled current from said second source to a receiver, and includingat the receiver means for receiving said signals, deriving therefromcorresponding controlled currents, and an intermittently recordingelement whose functioning is determined by said current,- so that saidrecording element Will be non-operative during the intervals when it isnot actually recording sig- A nals corresponding to the modulatedcurrent from said photo electric means, in one direction.

`5. 'A facsimile transmitting and receiving system comprising at thetransmitter, means for scanning an image, compensated photoelectricmeans for generating currents corresponding to scanned light values ofsaid image, means for 'generating 'signal impulses having a frequencygreater than .said currents corresponding to said light values, buthaving a frequency less than the frequency employed between thetransmitter and the receiver, means for modulating said series of signalimpulses according to said light vaines, means for modulating'v saidimpulses ining to said light values 'and non-recording means dependentlyof said lightV values, means forV imcontrolled by said independentmodulations, subposingvsaidrmodulated impulses upon transmisstantiallyas described. l V l sion carrier-,current of substantially higherv fre--v JOHN V. L. HOGAN.

quency and, at the receiver, means for recording controlled by saidsignals modulated accord- HORACE G.VMI1LER.

cEmFcAtvE OF CONNECTION.Y

f March 7, 1959.

JOHN v. L. HOGAN, ET AL. n

Patent No. 2,119,292.

it .is hereby -certif1ed thatV error appears `:in the printedspecification of the above 'numbered patent requiring correctionasfollows: Page 5, seeond column, line 6h. clamli, strike out `the commeand words 1n one diand rthat the saidV Letters Patent should be readwith this cor.- i

reoton" he case-in the eortion'therenthat theYsaxne-'niay conform to therecord oft Patent Offiee. 'Y Y Signed and sealed this V17th day ofDecember, A. D. 1911.0.

Henry Van Arsdale, ActngCommissoner of Patents.

